A common mode choke coil disclosed in Japanese Patent No. 4209851, for example, is known as one disclosure regarding related-art common mode filters. FIG. 12 is a sectional structural view of a common mode choke coil 510 disclosed in Japanese Patent No. 4209851.
The common mode choke coil 510 comprises a multilayer body 512 and coils 514, 516 and 518. In a plan view, the coils 514, 516 and 518 extend from the outer peripheral side toward the inner peripheral side in a substantially spiral shape while circling clockwise, and they are overlapped with one another. The coil 518 is sandwiched between the coils 514 and 516 from the upper and lower sides. In the common mode choke coil 510, a high frequency signal is transferred to each of the coils 514 and 516, and a ground potential is connected to the coil 518.